We report the synthesis of N-doped TiO(2) nanofibers and high photocatalytic efficiency in generating hydrogen from ethanol-water mixtures under UV-A and UV-B irradiation. Titanate nanofibers synthesized by hydrothermal method are annealed in air and/or ammonia to achieve N-doped anatase fibers. Depending on the synthesis route, either interstitial N atoms or new N-Ti bonds appear in the lattice, resulting in slight lattice expansion as shown by XPS and HR-TEM analysis, respectively. These nanofibers were then used as support for Pd and Pt nanoparticles deposited with wet impregnation followed by calcination and reduction. In the hydrogen generation tests, the N-doped samples were clearly outperforming their undoped counterparts, showing remarkable efficiency not only under UV-B but also with UV-A illumination. When 100 mg of catalyst (N-doped TiO(2) nanofiber decorated with Pt nanoparticles) was applied to 1 L of water-ethanol mixture, the H(2) evolution rates were as high as 700 μmol/h (UV-A) and 2250 μmol/h (UV-B) corresponding to photo energy conversion percentages of ∼3.6 and ∼12.3%, respectively.

Elongated oxide nanostructures have gained much attention in the past decade due to their unique mechanical, optical, and electrical properties. Despite the vast amount of theoretical and experimental work on these materials, the mechanism of water-related electrical conduction in these systems has remained unsolved. In this study, the charge transport processes in hydrothermally synthesized trititanate nanowires (TiONW) at varying relative humidity (RH) have been investigated. Parameters characterizing these processes were extracted from dielectric spectroscopy (DRS) and ionic transient current (ITIC) measurements at room temperature. The dc conductivity varies exponentially with increasing RH. It is suggested to stem mainly from the exponentially increasing charge carrier concentration, while carrier mobility seems to have a much weaker influence on the long-range charge transport. The changes in the constituent parameters of dc conductivity are thought to be due to the changes in the amount, surface structure, and thermodynamic state of adsorbed water, which has been confirmed in the case of ionic mobility with moisture sorption and calorimetric (DSC) investigations. However, the microscopic origin of the exponentially increasing carrier concentration with RH still remains an open question.

At small food processing facilities, the most frequently used test to determine if grain-derived mycotoxin concentrations are compliant with legal limits is the enzyme-linked immunosorbent assay (ELISA). Each kit is designed to detect one of the six dangerous mycotoxins. With the increasing occurrence of coinfection of grain with multiple-mycotoxins in the field and/or during storage, ELISA is no longer a cost effective best assay option. With ELISA, each species of mycotoxin requires different sample preparation/extraction and a 45 min incubation. The alternative multiplexed assay presented here, the competitive fluorescent microsphere immunoassay (CFIA), follows current food safety standards. It handles several toxins simultaneously with a single universal extraction protocol. The authors' objective was to modify an existing commercial CFIA kit developed for bench top flow cytometry and extend its utility for point-of-need (PON) applications. The accelerated protocol offers over 60% reduction in total processing time and it detects dual mycotoxin contamination simultaneously. The observed enhanced binding kinetics equations reported here utilizing suspended solid phase particles in liquid phase, are also supported by published theoretical calculations. In the near future portable cytometry may bring rapid multiplexed PON testing to assure the safety of small food processing installations. © 2016 International Society for Advancement of Cytometry.